"She wasn't feeling well enough to do dress rehearsal," said one ABC rep, "and only decided that she would dance 15 minutes before she went on." Vanderpump, whose husband and daughter were in the audience, was immediately whisked away after the show, "to go home to bed and chicken soup."

If she hadn't danced on the show, elimination Tuesday night would have been inevitable: Without footage from dress rehearsal, the judges, who can score a dress rehearsal in an emergency, had nothing to judge. And without dancing live on the show, she would've scored a zero. So Vanderpump decided to soldier on.

"I saw her just before she went out," says pro Derek Hough. "And I said, 'You look fantastic. You don't look like you're sick. If worst comes to worst, you go out there, you forget everything. Nobody here or at home is judging you negatively. Everyone is rooting for you. So take the pressure off yourself and just power through, because you'll regret it more if you don't.'"

Vanderpump ended up looking weak and confused with the steps; she was only able to pull off a score of 18, tying with boxer Victor Ortiz for last place. "I think it's hard," says Aly Raisman, the Olympic gymnast who came out on top of the leader board for the first time Monday night with a stunning contemporary dance. "But I think Lisa showed real mental toughness. I mean, that's not easy: Getting out there and dancing the cha cha is scary as it is. But being sick and not well-rehearsed? Everything is going to feel off. And dancing in heels? She's obviously not used to that. I have so much respect for her."